Ordinarily, a track ball, a joy stick, a mouse or the like have been widely used as devices for inputting coordinates or directions for a computer.
However, in the case of a conventional mouse, as a ball in the mouse is rolled and the quantity of the displacement is mechanically detected, it requires a certain range of smooth surface to be operated.
Although a conventional joy stick does not occupy much space, its movable portion has a limited range, which makes it difficult to use for performing minute input operations.
A conventional track ball does not have the problems as described above but it is difficult to operate the buttons on the track ball and the track ball itself simultaneously.
Further, though these devices are intrinsically two-dimensional dimensional input devices, there are conventional devices which have been modified into three-dimensional input devices (refer to unexamined Japanese published patent application No. 62-40619 for a track ball which represents such a case). However, since these three-dimensional devices are obtained by modifying intrinsically two-dimensional devices, they require the operator to perform unnatural operations that are different from what the operator intends.
As a device for three-dimensional input operations on a non-contact basis, for example, unexamined Japanese published patent application No. 1-96720 discloses a coordinate input device utilizing an acceleration sensor. When this device is manually put in a translation motion, it detects the motion from the acceleration. It does not provide information regarding rotation and is apt to generate operational errors, and it is expensive because it performs complicated operations wherein the acceleration must be integrated twice to be converted into position coordinates.
It is an object of the present invention to provide a non-contact multidimensional information input device which solves the above-mentioned problems and allows input to be made in a way that the operator intends with high accuracy at low cost and without restrictions on the place in which it is used.